CN116117741A - A device and method for dismantling a blind hole bushing - Google Patents

Abstract

The invention provides a device and a method for disassembling a blind hole bushing, and relates to the technical field of bushing disassembly. The nut sleeve is internally provided with a threaded hole, the outer side of the lower part of the nut sleeve is provided with a plurality of hanging seats, the distance between each hanging seat and the adjacent hanging seat is the same, each hanging seat comprises two identical lifting lugs, a first bolt hole is formed in each lifting lug, a torsion spring hole is formed in the rear side position below each bolt hole, the hanging seats are connected with a lifting hook, the upper part of the lifting hook is provided with a second bolt hole, and the bolts penetrate through the first bolt holes and the second bolt holes and are fixed by nuts. The invention has the advantages of simple structure, no damage to blind holes and bushings, capability of disassembling bushings with various specifications, strong universality and stable and reliable disassembly force.

Description

A device and method for dismantling a blind hole bushing

technical field

The invention relates to the technical field of bush removal, in particular to a device and method for removing a blind hole bush.

Background technique

In all kinds of mechanical equipment, it is more common to adopt the structural form of inserting bushes in blind holes, and the bushes embedded in the traction pin holes on the crank arm seat of the locomotive frame are more typical. A blind hole is arranged on the arm seat of the frame, and the blind hole is used for installing a traction pin to transmit traction force and braking force. During long-term use, in order to protect the draw pin hole on the frame crank seat from damage, a bushing is embedded in the draw pin hole on the frame crank seat. The bushing needs to be disassembled for flaw detection and inspection when the locomotive C5 is repaired.

An existing device for taking out a blind hole inner bushing comprises a thickened outer nut, a threaded sleeve, an elastic collet, a gasket, and an ejection screw. How to use: First put the tool into the bushing, screw the thickened outer nut onto the threaded sleeve, and clamp the elastic jacket through the shoulder of the threaded sleeve, the gasket and the shoulder of the elastic jacket. At this time, hold the thickened outer nut, turn the handle to move the ejection screw downwards, expand the elastic jacket and make its four claws grasp the inner hole of the bushing. Continue to turn the handle, and after the ejection screw touches the bottom of the blind hole, it is pulled up together with the elastic collet and the bushing, thereby taking out the bushing in the blind hole. However, this device has certain disadvantages: it is only suitable for the disassembly of a bushing with a diameter specification, and its application range is relatively limited, and it does not have universality; when the device clamps the bushing, the external force acts on the working surface of the inner ring of the bushing , it is very easy to cause damage to the working surface of the bushing; since the inner surface of the bushing is clamped by the elastic jacket, the clamping force is small, and it is not easy to take out the bushing with a large interference. .

Another existing method for removing the blind hole inner bushing is to weld an extension bolt on the inner wall of the bushing, and lift the end of the bolt by external force to disassemble the blind hole inner bushing. However, this method causes permanent damage to the blind hole inner bushing, and the bushing will no longer be usable. If you do not pay attention to protection, the use of electric welding can easily cause damage to the blind hole and the base body.

Contents of the invention

According to the above-mentioned technical problems that the removal scheme of the existing blind hole inner bushing has poor versatility and is easy to damage the bushing, a device and method for removing the blind hole bushing are provided. The invention mainly adopts a new device structure to realize the removal of bushes with various diameters and specifications, and at the same time lifts the bottom of the bushes with a hook, so as to disassemble the bushes without damaging the blind holes and bushes. Effect.

The technical means adopted in the present invention are as follows:

A device for disassembling blind hole bushings, including a nut sleeve, a lead screw, a special-shaped double torsion spring and a hook, the upper part of the nut sleeve is connected with the lead screw, and the lower part of the nut sleeve is connected with several hooks , A special-shaped double torsion spring is arranged between the lower part of the nut sleeve and the hook.

Further, a threaded hole is opened inside the nut sleeve, and the threaded hole inside the nut sleeve is adapted to and threadedly connected with the thread on the outside of the lead screw. Several hangers are arranged outside the lower part of the nut sleeve, and each hanger The distance between the seat and the adjacent hanging seat is the same, and each hanging seat includes two identical lifting lugs, and a first bolt hole is opened on the lifting lug, and a torsion spring hole is opened at the lower rear side of the bolt hole. The suspension seat is connected with the suspension hook, and the upper part of the suspension hook is provided with a second bolt hole, and the bolt is fixed by a nut after passing through the first bolt hole and the second bolt hole.

Further, a pin hole is opened below the second bolt hole, and a pin shaft is arranged in the pin shaft hole, and the spring end of the special-shaped double torsion spring is sleeved on both ends of the pin shaft protruding from the pin shaft hole. , the curved end of the special-shaped double torsion spring is clamped in the torsion spring hole.

Further, the outside of the upper end of the nut sleeve is square.

Further, a screw hole is opened on the upper part of the screw rod, and a handle is arranged through the screw rod hole.

Further, the diameter of the torsion spring hole is 1.2mm.

Further, the lower part of the hook is a hook-shaped structure, the angle between the upper hook surface of the hook-shaped structure and the hook rod body is 100°, and the distance between the upper hook surface and the lower hook surface of the hook-shaped structure is 3mm.

Further, the handle is in clearance fit with the screw hole; the pin shaft is in clearance fit with the pin shaft hole; and the bolt is in clearance fit with the second bolt hole.

Further, the torque of the special-shaped double torsion spring satisfies:

Among them: T is the torque of a single special-shaped double torsion spring, f is the contact pressure and extraction force of the blind hole bushing, L is the length of the hook, and D is the inner diameter of the blind hole bushing;

The torsional stiffness of the special-shaped double torsion spring is:

Among them: K is the torsional stiffness, κ is the initial coefficient, E is the elastic modulus of the material, d is the diameter of the spring wire, and n ₁ is the initial effective number of turns of the torsion spring.

The present invention also provides a method for using the device for dismantling the blind hole bushing, which is realized based on the above-mentioned device for disassembling the blind hole bushing, including the following steps:

Extend the hook of the device into the inner wall of the blind hole bushing, the inner wall compresses the hook to shrink the special-shaped double torsion spring, and the supporting hook structure is on the inner wall of the blind hole bushing;

When the device is lowered, when the upper end surface of the hook structure is lower than the lower end surface of the blind hole bushing, the special-shaped double torsion spring rebounds so that the hook expands outward and hooks the lower end surface of the blind hole bushing;

Use a wrench or caliper to clamp the square structure at the upper end of the nut sleeve to prevent it from rotating;

Turn the handle so that the lower end of the lead screw is clamped on the bottom of the blind hole;

Continue to turn the handle to make the nut sleeve move upward relative to the lead screw, and the nut sleeve drives the hook to move the blind hole bushing upward until it is completely separated from the blind hole, and the disassembly work is completed.

Compared with the prior art, the present invention has the following advantages:

1. The present invention sets the device of the hook and the lifting hook, which is different from the traditional device that uses the disassembly force on the inner surface of the bush. The disassembly force of the present invention directly acts on the end face of the bush, so it will not affect the blind hole lining. damage to the working surface;

2. By setting special-shaped double torsion springs and hooks, the present invention can realize the disassembly of blind hole bushings in various specifications and has high versatility;

3. The present invention has simple structure, low manufacturing cost, simple appearance and is suitable for small space operation.

4. In the present invention, the threaded rod is provided, and the handle on the threaded rod is rotated to raise the nut cover to drive the blind hole bushing to rise, so that the dismounting force of the present invention is more stable.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is a front view of the device of the present invention.

Figure 2 is a partial enlarged view of Figure 1.

Fig. 3 is a working diagram of disassembling a blind hole according to the present invention.

FIG. 4 is a partially enlarged view of FIG. 3 .

Fig. 5 is a front view of the nut sleeve of the present invention.

Fig. 6 is a bottom view of the nut sleeve of the present invention.

Fig. 7 is a top view of the nut sleeve of the present invention.

Fig. 8 is a front view of the hook of the present invention.

FIG. 9 is a partially enlarged view of FIG. 8 .

Fig. 10 is a front view of the special-shaped double torsion spring of the present invention.

Fig. 11 is a side view of the special-shaped double torsion spring of the present invention.

Fig. 12 is a design schematic diagram of the special-shaped double torsion spring of the present invention.

In the figure: 1. handle; 2. lead screw; 3. nut sleeve; 4. bolt; 5. special-shaped double torsion spring; 6. hook; 7. pin shaft; 8. first bolt hole; 9. torsion spring hole ; 10, the second bolt hole; 11, the pin hole; 12, the blind hole bushing.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is only some embodiments of the present invention, but not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and in no way taken as limiting the invention, its application or uses. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. At the same time, it should be clear that, for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the authorized description. In all examples shown and discussed herein, any specific values should be construed as exemplary only, and not as limitations. Therefore, other examples of the exemplary embodiment may have different values. It should be noted that like numerals and letters denote like items in the following figures, therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

In the description of the present invention, it should be understood that orientation words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" etc. indicate the orientation Or positional relationship is generally based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description. In the absence of a contrary statement, these orientation words do not indicate or imply the device or element referred to. It must have a specific orientation or be constructed and operated in a specific orientation, so it should not be construed as limiting the scope of the present invention: the orientation words "inside and outside" refer to inside and outside relative to the outline of each part itself.

In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing corresponding components. To limit the protection scope of the present invention.

As shown in Figure 1-11, the present invention provides a device for removing blind hole bushings, which can be used to remove blind hole bushings with an inner diameter of 50-170 mm and a height of 10-120 mm, including nut sleeves 3, wire Bar 2, special-shaped double torsion spring 5 and hook 6, the upper part of the screw mandrel is provided with a screw mandrel hole, and a handle 1 is arranged through the said screw mandrel hole. The inner side of the nut cover 3 is connected with the lead screw 2 , the bottom of the nut cover 3 is connected with three suspension hooks 6 , and a special-shaped double torsion spring 5 is arranged between the bottom of the nut cover 3 and the suspension hooks 6 . The inside of the nut sleeve 3 is provided with a threaded hole, and the threaded hole inside the nut sleeve 3 is matched with the thread on the outside of the lead screw 2 and is threadedly connected. The distance between the seat and the adjacent hanging seat is the same, and each hanging seat includes two identical lifting lugs, and a first bolt hole 8 is opened on the lifting lug, and a torsion spring is opened at the lower and rear side of the first bolt hole 8. Hole 9 with a diameter of 1.2mm. The hanger is connected to the hook 6, and the upper part of the hook 6 is provided with a second bolt hole 10, and the bolt 4 is fixed by a nut after passing through the first bolt hole 8 and the second bolt hole 10. A pin hole 11 is provided below the second bolt hole 10, and a pin shaft 7 is arranged in the pin shaft hole 11, and the spring end of the special-shaped double torsion spring 5 is sleeved on the pin shaft 7 and protrudes from the pin shaft hole 11. On both ends of the special-shaped double torsion spring 5, the bent end is clamped in the torsion spring hole 9. Under the free state, the suspension hook 6 is in the state of expanding outward under the supporting action of the special-shaped double torsion spring 5 .

A method for using a device for removing a blind hole bushing, comprising the following steps:

Extend the hook 6 of the device into the inner wall of the blind hole bushing 12, and the inner wall compresses the hook 6 to make the special-shaped double torsion spring 5 contract. At this time, the special-shaped double torsion spring stores elastic potential energy, and the supporting hook structure is on the inner wall of the blind hole bushing 12 superior;

When the device is lowered, when the upper end surface of the hook structure is lower than the lower end surface of the blind hole bushing 12, the elastic potential energy stored in the special-shaped double torsion spring is released, and the special-shaped double torsion spring 5 rebounds so that the hook 6 expands outward and hooks the blind hole the lower end surface of the bushing 12;

Use a wrench or a caliper to clamp the square structure at the upper end of the nut sleeve 3 to prevent it from rotating;

At the handle, the power source is provided by manpower to apply torque, and the handle 1 is rotated so that the lower end surface of the screw 2 is clamped on the bottom surface of the blind hole;

Continue to turn the handle 1 to make the nut cover 3 move upward relative to the lead screw 2, and the nut cover 3 drives the hook 6 to move the blind hole bushing 12 upward until it is completely separated from the blind hole, and the disassembly work is completed.

The blind hole bush removal device can complete the removal of blind hole bushes with an inner diameter of 50-170 mm and a height of 10-120 mm through the mutual cooperation of the hook and the special-shaped double torsion spring, and has high versatility.

Due to the structural characteristics of the hook hook, in order to ensure that the hook can hook the end face of the blind hole bushing 12, after the bushing is assembled in the blind hole, the distance "A" between the end face of the bushing and the bottom surface of the blind hole must be greater than 3mm. That is, the depth of the blind hole must be greater than the height of the bushing by more than 3mm.

The present invention also provides a design method of a device for dismounting a blind hole bushing, as shown in FIG. 12 . The stiffness design of the special-shaped double torsion spring is the focus of the structural design of this device. According to the initial design constraints of the detachable bushing with an inner diameter of 50-170mm and the hook length of 120mm, the following contents are included:

Input conditions: the inner diameter D of the blind hole bushing, the length L of the hook, the contact pressure and the extraction force f of the blind hole bushing.

Initial design input values: spring wire diameter d, initial effective number of turns of torsion spring n ₁ ,

The initial diameter of the torsion spring D1,

Design principle: ensure that the hook does not spring open during the removal of the bushing, that is, the component force of the torque generated by the torsion spring in the horizontal direction should be greater than the component force of the lifting force of the hook acting on the horizontal direction. Need to meet: the torque of a single torsion spring

Among them, the torque formula of the torsion spring: T=K×ψ, ψ is the torsion angle.

The formula for calculating the torsional stiffness of a torsion spring is:

Output: the torsional stiffness value K of the torsion spring, the diameter of the spring wire d, and the initial effective number of turns of the torsion spring n1.

Example

Figure 1-2 shows a schematic diagram of a blind hole bush removal device provided by the present invention, which consists of a handle 1, a screw 2, a nut sleeve 3, a special-shaped double torsion spring 5, a hook 6, a pin shaft 7, etc. composition. Fig. 3-4 shows the schematic view of the blind hole bush removal device in working state.

The lead screw 2 adopts a serrated thread, and a through hole is arranged at one end thereof for installing the handle 1 . In this invention, the length of the lead screw is 320mm, thus the disassembly of the blind hole bushing within the range of height 10-120mm can be realized. In fact, the lengthened or shortened lead screw can also be replaced according to the different operating space. The material of the lead screw is high-carbon alloy steel, and the surface hardness and mechanical properties of the material are improved by induction heat treatment.

As shown in Figure 5-7, the inner side of the nut sleeve 3 is a thread type matched with the lead screw, which adopts a serrated thread structure; the outer end of the nut sleeve 3 is evenly distributed with three hangers for connecting the hook 6; The other end of the outside is a square structure, so that the nut sleeve can be clamped with a wrench or a caliper to prevent it from rotating when it is in working condition; there is a φ1.2 hole on the left and right sides of each hanger, which is used to install special-shaped Double torsion spring 5. The nut sleeve is made of low-carbon alloy steel, and the surface hardness and mechanical properties of the material are improved through carburizing and quenching heat treatment hardening.

As shown in Fig. 8-9, a through hole is set on the hook 6 for installing the bearing pin 7 and the special-shaped double torsion spring 5. The hook shape at the end of the hook is specially designed: the upper hook surface and the hook rod body are at 100° to ensure that the end face of the bush with an inner diameter of 50 to 170mm can still be effectively clamped when the minimum inner diameter of the blind hole bushing is 50mm; the hook The thickness of the upper hook surface and the lower hook surface is 3 mm. In order to ensure that the hook can hook the end surface of the blind hole bushing 3, it must be ensured that after the bushing is assembled into the blind hole, the distance between the bushing end surface and the bottom surface of the blind hole must be Greater than 3mm, that is, the depth of the blind hole must be greater than the height of the bushing by more than 3mm. The hook is made of high-quality alloy steel, which is hardened by heat treatment through overall carburizing and quenching to improve the surface hardness and mechanical properties of the material.

As shown in Figure 10-11, the spring wire diameter of the special-shaped double torsion spring 5 is φ1, one end of which is installed on the pin shaft 7, and the other end is stuck in the blind holes of φ1.2 on the left and right sides of the hanging seat on the nut sleeve 3.

The through hole on the handle 1 and the leading screw 2 is a clearance fit; the through hole on the pin shaft 7 and the suspension hook 6 is a clearance fit; the outer diameter of the polished rod of the bolt 4 and the through hole on the suspension hook 6 are a clearance fit.

The working states of the different stages of the blind hole bush removal device of this invention are as follows: in the free state, the special-shaped double torsion spring is in a non-telescopic state, and the 3 hooks at this time are in the outer shape under the support of the special-shaped double torsion spring. Expanded state; when the three hooks extend into the inner wall of the blind hole bushing, the special-shaped double torsion spring is in a compressed state to store elastic potential energy, so that the hooks are supported on the inner wall of the blind hole bushing, and the whole is gradually lowered ; When the hook exceeds the end face of the blind hole bushing, the special-shaped double torsion spring is still in a compressed state but the stored elastic potential energy is released, and the hook will expand outward and hook the end face of the blind hole bushing 3; in the handle The torque is applied by a power source provided by manpower, and the end face of the lead screw will be clamped on the bottom surface of the blind hole on the arm seat of the frame; when the torque continues to be applied, the nut sleeve will move upward relative to the lead screw, and the nut sleeve will drive the hook to close the blind hole. The bush is gradually lifted until it is completely out of the blind hole, and the disassembly of the blind hole inner bush is completed.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (10)

1. A device for dismounting a blind hole bushing, characterized in that it comprises a nut cover (3), a leading screw (2), a special-shaped double torsion spring (5) and a suspension hook (6), and the nut cover ( The inside of 3) is connected with the lead screw (2), the lower part of the nut sleeve (3) is connected with several hooks (6), and a special-shaped Double torsion spring (5). 2. The device for dismounting a blind hole bushing according to claim 1, characterized in that, the inside of the nut sleeve (3) is provided with a threaded hole, and the threaded hole inside the nut sleeve (3) is connected with the lead screw (2) The external thread is matched and threaded, and the outside of the lower part of the nut sleeve (3) is provided with several hanging seats, each hanging seat has the same spacing as the adjacent hanging seat, and each hanging seat includes two identical hanging seats. Lifting lug, the first bolt hole (8) is opened on the said lifting lug, the torsion spring hole (9) is opened at the lower rear side of the first bolt hole (8), and the hanging seat and the hook (6 ), the upper part of the hook (6) is provided with a second bolt hole (10), and the bolt (4) is fixed by a nut after passing through the first bolt hole (8) and the second bolt hole (10). 3. The device for dismounting a blind hole bushing according to claim 2, characterized in that a pin hole (11) is opened below the second bolt hole (10), and the pin hole (11) A pin shaft (7) is arranged inside, and the spring end of the special-shaped double torsion spring (5) is sleeved on the two ends of the pin shaft (7) protruding from the pin shaft hole (11), and the special-shaped double torsion spring (5) ) is clamped in the torsion spring hole (9). 4. The device for dismounting a blind hole bushing according to claim 1, characterized in that, the outside of the upper end of the nut sleeve (3) is square. 5 . The device for removing the blind hole bushing according to claim 3 , wherein a screw hole is opened on the upper part of the screw rod, and a handle ( 1 ) is arranged through the screw rod hole. 6 . 6. The device for dismounting a blind hole bushing according to claim 3, characterized in that the diameter of the torsion spring hole (9) is 1.2 mm. 7. The device for dismounting a blind hole bushing according to claim 1, characterized in that, the lower part of the hook (6) is a hook-shaped structure, and the upper hook surface of the hook-shaped structure is in contact with the hook (6). ) The angle α between the rod bodies is 100°, and the distance h between the upper hook surface and the lower hook surface of the hook structure is 3mm. 8. The device for removing the blind hole bushing according to claim 5, characterized in that, the handle (1) is in clearance fit with the screw hole; the pin shaft (7) and the pin shaft hole (11) Clearance fit: the bolt (4) is in clearance fit with the second bolt hole (10). 9. The device for dismounting a blind hole bushing according to claim 1, characterized in that, the torque of the special-shaped double torsion spring (5) satisfies:

Among them: T is the torque of a single special-shaped double torsion spring, f is the contact pressure and extraction force of the blind hole bushing, L is the length of the hook, and D is the inner diameter of the blind hole bushing; The torsional rigidity of described special-shaped double torsion spring (5) is:

Among them: K is the torsional stiffness, κ is the initial coefficient, E is the elastic modulus of the material, d is the diameter of the spring wire, and n ₁ is the initial effective number of turns of the torsion spring. 10. A method for using a device for dismounting a blind hole bushing, realized based on the device for dismounting a blind hole bushing according to claims 1-9, characterized in that it comprises the following steps: Extend the hook (6) of the device into the inner wall of the blind hole bushing, the inner wall compresses the hook (6) to shrink the special-shaped double torsion spring (5), and supports the hook-like structure on the inner wall of the blind hole bushing; When the device is lowered, when the upper end surface of the hook structure is lower than the lower end surface of the blind hole bushing, the special-shaped double torsion spring (5) rebounds so that the hook (6) expands outward and hooks the lower end surface of the blind hole bushing; Clamp the square structure on the upper end of the nut sleeve (3) with a wrench or a caliper to prevent it from rotating; Turn the handle (1) so that the lower end surface of the lead screw (2) is clamped on the bottom surface of the blind hole; Continue to turn the handle (1) to make the nut sleeve (3) move upward relative to the lead screw (2), and the nut sleeve (3) drives the hook (6) to move the blind hole bushing upward until it is completely out of the blind hole. job done.

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